The present invention relates to rotary regenerative heat exchangers, and more particularly, to an element basket adapted to facilitate removing element baskets from or placing element baskets into a rotary regenerative heat exchanger.
A rotary regenerative heat exchanger comprises a rotor that carries heat transfer material that is alternately rotated first into a hot gas stream to absorb heat therefrom and then into a cooler gas stream to impart heat thereto. The heat exchange material carried by the rotor generally comprises a mass of heat absorbent plates. The plates are assembled in an orderly array and positioned within element baskets that firmly hold the plates in a predetermined space relationship in order that they may be easily handled and arranged in the rotor of the rotary regenerative heat exchanger.
Hot gases, usually generated by combusting a fossil fuel in a furnace, pass into the heat exchanger and thence over the heat absorbent material contained therein. As the gas flows through the heat absorbent material, the heat absorbent material erodes, corrodes, becomes loosened in the element baskets, and becomes covered with particulate materials deposited from the combustion gases. Therefore, it is necessary that the element baskets be periodically removed and replaced.
In the prior art, it was necessary to provide a space between the center element holding bar and the end edges of the heating elements contained within a heating element basket such that a hook could be inserted therebetween for lifting the heating element basket. The prior art heating element basket lifting means provided a single point of support as a heating element basket was removed from or placed into the rotor. Since the heating element baskets are trapezoidal in cross sectional area such that lifting the heating element baskets from the center point of the center top element holding bar would result in a rotational moment that would cause the heating element basket to bind as the heating element basket was removed from or placed into the rotor. Locating the precise point along the top center element holding bar that would result in no moments and therefore eliminate binding would require a trial and error process and be virtually impossible when removing heating element baskets that have been subjected to erosion and particulate material buildup. Furthermore, the space required between the center element holding bar and the heating elements to accommodate the hook for lifting results in an undesirable empty space within the heat exchanger which cannot be used for heat exchange and, therefore, results in an increase is the overall height of the heat exchanger.